Improvement in making patterns for castings



w. E. CRAIGI- Making Patterns for Castings.

y Patented0ct. 26,l875.

' UNITED STATES PATENT QFFICE.

WILLIAM E. GRAIG, OF INDIANAPOLIS, INDIANA.

llVlPROVEMENT IN MAKING PATTERNS FOR CASTINGS. v

Specification forming part of Letters Patent No. 169,151, dated October 26, 1875 application filed August 28, 1875.

To all whom it may concern:

Be it known that I, WILLIAM E. CRAIG, of Indianapolis, in the county of Marion and State of Indiana, have invented a new and Improved Process of Forming the Patterns for Ornamental Castings, of which the following is a specification:

My invention consists of a new method of making elaborate patterns for ornamental ironwork, such as architectural work, flower-vases, fountains, or any intricate-shaped pattern for light, thin castings.

The object is to make such patterns cheaper than they can be carved in wood.

In the drawing, Figure l is an elevation of a pattern, which I first make in clay,of the object I wish to produce. Figs. 2 to 8, inclusive, are sections of molds, illustrating the different steps of my improved method.

Similar letters of reference indicate corresponding parts.

In the first place I model up the desired form A in ground potters clay, and, when set, take a plaster cast, B, from it; then roll a sheet, 0, of clay onv a gage-board, D, having ribs E, the thickness of the casting I wish to produce, which sheet I lay on the plaster cast B, and gently press it into the cast by hand all round, as represented in Fig. 4, and then cast upon it a back mold, F, of plaster, making a complete mold, in which, after suitably cleaning and soaking in water, I cast a pattern, G, of the following composition, viz: Bees-wax, red lead, and rosin, in about the proportions of three pounds wax, one pound lead, and a half-pound of rosin, melted over a slow fire. This pattern of composition I trim with a penknife, and putback on the back mold F, using it as a follow-board, and make thereon the said mold I, after which I make a sand mold, J, in the place of back mold F, and

in these sand molds cast the metal article K which I wish to produce.

By this plan considerable economy of labor is effected, as a workman can model up in clay more in one day than a carver can do in a week.

Having thus described my invention, I claim asnew and desire to secure by Letters Patent- The method of making elaborate ornamental castings by first modeling the form of the article to be produced in clay, as at A, taking a plaster mold, B, therefrom, applying to said mold a thin sheet of clay, G, forming thereon the back mold F, casting the composition pattern G in said plaster molds, and forming said molds I J from the composition pattern and plaster molds, all substantially as herein described.

WILLIAM E. CRAIG. Witnesses: J OSEPH RUMBoLD,

N. B. MoODY. 

